Recessed lighting fixtures typically include a frame attached to a structure such as a joist above the ceiling surface. One or more light elements are disposed in a reflector held by the frame that opens into the ceiling. Although it may include holes in which the light elements are secured and replaced, the reflector is typically an otherwise enclosed structure so that it defines a recess extending upward into a ceiling.
Generally, the reflector body is cylindrically shaped and has a flat top surface opposite the reflector's opening. Because of the flat top surface and placement of the light element near the top of the reflector, light is often trapped in the reflector. Thus, looking straight up into such a fixture, the reflector's top inside surface often appears dark.